Machine for rolling sheet metal shapes



Sept. 19, 1933. A. RAFTER 1,927,501

MACHINE FOR ROLLING SHEET METAL SHAPES Filed Feb. 2, 1932 INVENTOR.

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ATTORNEY- Patented Sept. 19, 1933 I v UN TED -;s;T A ITs-s 'PATENT.or ies c a 1 zt501- iVIACHINE' FOR ROLLING SHEET, METAL H SHAPES 7 Albert RaftegBelleville, N. J assignor to Rafter Machine Company, Belleville, N. J., a partnershipcompose'd of Albert Rafter and John V r i" Amman February 2, 1932. Serial 6. 590,355

roam. (or; L15328) a plurality of pairs of cooperating upper and lower die rolls. A strip of cold, metal is passed between one pair of die rolls to the following pair; the die rolls being progressively shaped to gradua ally form, the sheet metalstripinto the desired shape. The lower die rolls are substantially of h the same diameter, but theupper die rolls gradually increase in diameter,- and consequently the peripheral speed of the upper die rolls increases as the metal progresses through themachine, and all of the rolls are rotated at the same speed. The variation in the peripheral speedsof theupper die rolls is objectionable in "thatthe'various portions of the'metal strip are urged to move at different speeds resulting in buckling and bending of the sheet metal strip. Also, theupper die rolls slip over the metal, the slipping increasing as the diameters of the die rollsincreasaresulting in an undesired, an uneven, wearing of the die rolls which causes improper forming of the metal sheets. Inasmuch as die rolls are expensive and must be carefully and accurately made, it is essential that uneven wearing of the die rolls be eliminated. -Heret0fore, this has been accomplished by'providing gearing designed to drive the various die rolls at different and proper speeds; that is, to cause the peripheral speeds of all of the die rolls to be substantially the sameso that there will be no slipping or sliding of the metal sheet as it passes between the rolls. But as is obvious, gearing to produce the proper speeds for a given set of die rolls will be ineffective for another set of rolls; and consequently the equalizing of peripheral speeds by especially designed gearing is objectionable in that whenever it is desired to form the metal into a different shape it is necessary to rearrange the gearing. Such a procedure is very expensive and inconvenient, and inasmuch as manymanufacturers desire to use the same machine for making several different shapes, it is desirable that a machine be provided which is universal in its application.

It is, therefore, an object of this invention to provide a metal forming machine having a plurality of pairs of die rolls, all of, which rolls have substantially the same peripheral speed regardless of the diameters of the rolls.

A further object is the provision, in a meta forming machine, of friction clutch means interposed between each dieroll and the means'for. driving the roll, so that any undue force on the die roll due to difierence in speed between the die'roll and the metal sheet passing between the die rolls will cause the driving means to be automatically disconnected from the die roll.

. These and other advantageous objects, which Will'later appear, are accomplished by the simple and practical construction and arrangement of parts hereinafter described and exhibited in the accompanying drawing, forming part hereof, and in which:

Figure lis a fragmentary elevational view'of a a 7 cold metal forming machine of pairs of die rolls, I I

Figure 2 is a view, partly in section, of a'pair of die rolls and the driving means thereforembodying my invention, I v

Figure 3 is -a side elevational View taken on line 3+3 of Figure 2', f I Figure- 4' is a perspective View of frictional clutch merribers employed in the form shown in Figure 2, 1 I

Figure 5 is a-partly sectional view of a pair of die rolls and thedriving means therefor, em ploying a modified form of friction clutch, and Y Figure 6' is a perspective View of a conical element'of the frictional clutch shown in Figure 5.

Referring to the drawing, a cold metal forming having a plurality machine is shown in Figure l to have a plurality it is to be understood that in some instances these 1 machines fmay have ten, or more pairs of die rolls.

In Figure 2 is shown the general arrangement of a pair of die rolls '7 and 12, which are used,

for example, to form a strip of cold metal into a channel 30. The upper die roll 12 is fixed to a I shaft 19, and the lower roll '7 is fixed to a shaft 20, the shaft 19 being journalled in bearings 14, 16 and 18 respectively in the housings 13, 31, and 17 respectively; while the lower shaft is journalled in a bearing 15 in housing'13 and in similar hearings in housings 31, 17. Shafts19 and 20 are rotated at the same angular speed by means of driving means (not shown) engaging the gears 22, 21, which gears in turn are in mesh with pinions 23, 24, the latter being in mesh with gears similar to the gears 22, 21 on the next succeeding die roll unit, so that all of the die rolls on the machine are rotated substantially at the same angular speed. The lower die rolls 7 of the machine, being of the same diameter, consequently have the same peripheral speed. But the upper die rolls 8, 9, 10, 11 and 12 being of different diameters, naturally'have different-pe ripheral speeds; and the difference in the peripheral speeds is compensated for by means hereinafter described. i

The driven gear 22 on upper shaft .19 is shown in Figure 2, to be loosely mounted and to have an inwardly projecting centrally positioned an,- hular flange 22' which is in frictional engagement with the flanges 28, 29, of the collars 28', 29,

(see Fig. 4) the collars being on opposite sides of the flange 22 and splined to the shaft 19. A compression spring 27 bears against flange 28 andurges the latter constantly into engagement with the annular flange 22, the flange 29 of collar 29 being restricted in movement in one direc tion by contact with the bearing 16.

The shaft 19 is threaded at 25 and carries a threaded nut 26 which engages the spring 27 and serves asmeans for adjusting the tensionofthe spring. v In operation, when resistance is encountered by the roll 12 due to the difference in'peripheral speeds of rolls '7 and 12, and a metal strip passing through the machine, flange 22' slips over the flanges 28, 29 against the pressure of spring 27,

so that While gear 22 will be rotated at a constant speed,.the rotary speedof. shaft 19 and die roll 12 will be varied to cause equalization of the peripheral speeds of die rolls '7 and '12.

" clutchin which a drivengear 40 has an annular wedge-shaped flange 4lwhich is engaged on opposite sides by conical members 42, (see, Fig. 6) which are splined to shaft 19, the conical members corresponding to the collars 28', 29 and flanges 28, 29 shown in Figures 2 and 4, and are maintained in contact with wedge-shaped flange 41 by compression spring 2'7 as above described. Obviously, it is not essential that the friction clutch members be located in connection with the driven gears as shown in Figures 2 and 5, but may be placed any place between the driving means and the die roll and accomplish substantially the the difference between the peripheral speed of the die roll and the speed of the strip of metal passing' between the upper and lower rolls. It is also clear that the friction means may be applied to the lower die roll as well as to the upper die roll and produce the same result, without departing from the spirit of the invention.

From the above description itwill be seen that I have provided effective means for equalizing the speeds of the die rolls of a cold metal forming machine, which means are the same regardless of the die rolls used, and which require nochange of gearing or other parts when it is desired to form different shapes on the same machine.

The foregoing disclosure is tobe regarded as descriptive and illustrative only, andnot as restrictive or. limitativeof the invention, of which obviously an embodiment may be constructed including many modifications without departing from the general scope herein indicatedand de noted in the appended claim.

Having thus described my invention, what. I

claim as new and. desire to secure by Letters Patent, is: 1 I

In a machine for forming cold metal into'desired shapes, an upper shaft and a lower shaft, die rolls of different diameters mounted on said shafts, gears to drive the shafts, means to rotate the gears at the same angular speed, the gear on the upper shaft having an inwardly projecting annular flange, a collar attached to the upper shaft and frictionally engaging one side of the flange, a second collar splined to the upper shaft, and resilient means normally urgingsaid second collarinto frictional engagement with the other side of the flange. l ALBERT RAFTER. 

